/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;

import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/**
 * Creates map entries using sample keys and sample values.
 *
 * @author Jesse Wilson
 */
@GwtCompatible
public abstract class TestMapEntrySetGenerator<K, V> implements TestSetGenerator<Map.Entry<K, V>>
{
    private final SampleElements<K> keys;
    private final SampleElements<V> values;

    protected TestMapEntrySetGenerator(SampleElements<K> keys, SampleElements<V> values)
    {
        this.keys = keys;
        this.values = values;
    }

    @Override
    public SampleElements<Entry<K, V>> samples()
    {
        return SampleElements.mapEntries(keys, values);
    }

    @Override
    public Set<Entry<K, V>> create(Object... elements)
    {
        Entry<K, V>[] entries = createArray(elements.length);
        System.arraycopy(elements, 0, entries, 0, elements.length);
        return createFromEntries(entries);
    }

    public abstract Set<Entry<K, V>> createFromEntries(Entry<K, V>[] entries);

    @Override
    @SuppressWarnings("unchecked") // generic arrays make typesafety sad
    public Entry<K, V>[] createArray(int length)
    {
        return new Entry[length];
    }

    /**
     * Returns the original element list, unchanged.
     */
    @Override
    public List<Entry<K, V>> order(List<Entry<K, V>> insertionOrder)
    {
        return insertionOrder;
    }
}
